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Decision-making process for the construction of hydroelectric plants in the north of Brazil

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In Brazil, the hydroelectric production is responsible for 63.84% of all the generation capacity of electrical energy and for decades is key to the country’s economic development. However, mistaken decisions with regard to the deployment of the necessary infrastructures have generated serious territorial consequences.

Throughout the recent Brazilian history, an overvaluation of the profits from the plants and an underestimation of the environmental, social and even financial costs prevailed. It is also possible to notice that many times the promises to cancel the construction of reservoirs or to reduce their capacity, especially when there is public pressure, usually do not come true when the start date for works arrives. This happened with the Plant of Belo Mountain on the Xingu River, whose capacity had been reduced from 11.183 MW to 5.500MW in 2006, but, in its final configuration, offered 11.233 MW.

The Ministry of Mines and Energy is the institution accountable for planning the energetic production in Brazil. Historically, the government has showed through this state organ an incessant ambition by the expansion of the hydroelectric production, since 1987, when it unveiled the National Plan of Electrical Energy 1987/2010, establishing the construction of 79 dams and the flooding of 10 million hectares, until today, as the Decennial Plan of Energetic Expansion 2012 – 2021 still predicts the construction of 17 new reservoirs.

The main social and environmental impacts of the establishment of hydroelectric plants arise from the need of construction of dams. Among the social impacts are effects on the native population, because of the loss of fishes and of other inputs from the river, the loss for the communities downstream of the availability of water and damages on fishing and agriculture, the spread of diseases, transmitted by mosquitos whose population grows in the reservoirs and the resettlement of urban and rural populations. In the case of the resettlement of the Amazonian traditional populations, the issue is even more severe, because, as they lived for generations in the same location, their lifestyle and skills, like fishing, may be incompatible in other regions.

Regarding the main environmental impacts, it is relevant to mention the loss of vegetation by the flooding, the later deforestation, the emission of GHE gases by the decomposition of the flora at the flooded regions and the mercury contamination of fishes and the population.

Many of these problems arise due to errors during the planning process and to the lack of public participation. An emblematic example is the Tucuruí Hydroelectric Plant. Created in 1984 in the State of Pará and initially with a capacity of 4.000 MW, its social and environmental damages were so high and disproportional to its benefits, that the Brazilian government was condemned even by the International Water Court.

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Picture 2. The Tucuruí dam and oriental legal Amazon (Source: M. Fearnside, Philip. Hidrelétricas na Amazônia: Impactos Ambientais e Sociais na Tomada de Decisões sobre Grandes Obras. Vol. 1 – p. 38)

One of its greater issues was the beginning of the works without an environmental impact evaluation, created only months later and superficially. This justifies why the number of displaced people went from 9.500 during the preliminary studies to 32.871 after the flooding of the 2.430 km² dam. Topographical errors also caused the removal of 3.700 people already resettled after their new homes were flooded during the reservoir’s filling. In regard to the native population, areas inhabited by three tribes were flooded and 36% of the total area submerged was originally occupied by the Parakanã Indians, Other communities were also affected indirectly.

Concerning environmental impacts, the forest loss surpasses the 2.430 m² because of the deforestation caused by new inhabitants and economic activities attracted by the plant. There are even more concerns, like emission of GHE gases, erosion and drastic reduction in the diversity of fishes. Among the main reasons is the small amplitude of the environmental impact analysis, not only in terms of the quantity of aspects considered but also regarding the projection period, as it was limited to the initial phase of construction.

As can be seen, the decision-making process regarding the construction of hydroelectric plants needs profound chances in order to prevent the selection of alternatives that result in social injustice, environmental destruction and despicable local gains. So, in this sense, effective popular participation throughout the planning process should be stimulated. The reduction of political pressure on the environmental organs and the creation of mechanisms to allow independent environmental impact evaluation are also possible solutions.

A change in the electric power production shares in Brazil, as foreseen in a report from Bloomberg New Energy Finance (BNEF), will also be able to contribute to minimize the impacts from energy production on the territory, as in 25 years, the participation of the wind and solar power, characterized by microgeneration units, will exceed the hydroelectric share.

The next steps taken by Brazil are crucial, not only due to their potential impacts on the Amazonian region, but also because, as a key investor in many hydroelectric projects in Latin America, it has the power to start new trends in international scale.



M. Fearnside, Philip. Hidrelétricas na Amazônia: Impactos Ambientais e Sociais na Tomada de Decisões sobre Grandes Obras. Vol. 1. Manaus: Editora INPA, 2015

Salgueirinho Osório De Andrade Guerra, José Baltazar; et al. Future scenarios and trends in energy generation in Brazil: supply and demand and mitigation forecasts. Santa Catarina: 2014

Plano Nacional de Energia Elétrica 1987/2010 – Ministério de Minas e Energia

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